It's happened before, and it could happen again. Tens of thousands of years ago, a giant ice sheet in Antarctic melted, raising sea levels by up to 30 feet around the world. This inundated huge swaths of what had been dry land. Scientists think it could happen again as the world heats up because of man-made global warming, new research suggests. Such a collapse would again cause seas to rise dramatically, which would lead to a global flood. Read more...